Is it considered bad Postgresql practice to have a column name that begins with the underscore character ("_")? I'm not sure where this is documented, but I'm seeing that Postgresql accepts prepending an underscore to a data type name as a kind of alias for appending [] to define an array data type. So even though Postgresql doesn't seem to have this problem, a human reader might confuse a column name beginning with _ as an array data type reference. Here is why I want to have some column names beginning with "_". I'm designing a database to shadow a public agency's data. I need some columns that reflect *my* shadow copy of the data, (like say download date) that don't have any semantic import with respect to the original data. Beginning such columns with "_" is a simple way to keep the column names uncluttered but indicate to the reader that the column applies to *my copy* but are not columns in the original data. Comments?